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Francis W. L. Esmonde-White

Francis W. L. Esmonde-White

PhD chemistry

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32
Publications
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532
Citations

Publications

Publications (32)
Article
Incidences of low-trauma fractures among osteopenic women may be related to changes in bone quality. In this blinded, prospective-controlled study, compositional and heterogeneity contributors of bone quality to fracture risk were examined. We hypothesize that Raman spectroscopy can differentiate between osteopenic women with one or more fractures...
Article
Spectroscopy rapidly captures a large amount of data that is not directly interpretable. Principal Components Analysis (PCA) is widely used to simplify complex spectral datasets into comprehensible information by identifying recurring patterns in the data with minimal loss of information. The linear algebra underpinning PCA is not well understood b...
Article
Full-text available
Fiber optics coupled to components such as lenses and mirrors have seen extensive use as probes for Raman and fluorescence measurements. Probes can be placed directly on or into a sample to allow for simplified and remote application of these optical techniques. The size and complexity of such probes however limits their application. We have used m...
Article
Microstress in reaction-bonded silicon carbide (RBSiC) has been measured using piezo-Raman spectroscopy. Compressive microstresses as high as 2 GPa exist in the silicon phase and tensile microstresses as high as 2.3 GPa exist in the SiC phase of RBSiC. This is much larger than expected for thermoelastic microstress from coefficient of thermal expan...
Article
Full-text available
Combining diffuse optical tomography methods with Raman spectroscopy of tissue provides the ability for in vivo measurements of chemical and molecular characteristics, which have the potential for being useful in diagnostic imaging. In this study a system for Raman tomography was developed and tested. A third generation microCT coupled system was d...
Article
Full-text available
Time-resolved and spatially offset Raman spectroscopies have previously been demonstrated for depth analysis through strongly scattering, non-transparent materials. In this study, several series of tissue phantoms were created with varied compositions and thicknesses to compare the potential of these different Raman techniques for biomedical applic...
Article
Full-text available
Sessile drop formation, also called drop deposition, has been studied as a potential medical diagnostic, but the effects of complex biofluid rheology on the final deposition pattern are not well understood. We studied two model biofluids, blood plasma and synovial fluid, when deposited onto slightly hydrophilic substrates forming a contact angle of...
Article
Full-text available
OBJECTIVE Osteomyelitis in the diabetic foot is a major risk factor for amputation, but there is a limited understanding of early stage infection, impeding limb-preserving diagnoses. We hypothesized that bone composition measurements provide insight into the early pathophysiology of diabetic osteomyelitis.RESEARCH DESIGN AND METHODS Compositional a...
Article
Full-text available
We report an overlooked source of artifacts for clinical specimens, where unexpected and normally negligible contaminants can skew the interpretation of results. During an ongoing study of bone fragments from diabetic osteomyelitis, strong Raman signatures were found, which did not correspond with normal bone mineral or matrix. In a bone biopsy fro...
Conference Paper
Raman spectroscopy can non-destructively measure properties of bone related to mineral density, mineral composition, and collagen composition. Bone properties can be measured through the skin in animal and human subjects, but correlations between the transcutaneous and exposed bone measurements have only been reported for human cadavers. In this st...
Chapter
Cortical bone is a unique and dynamic tissue due to its complex micro-architecture, structural role in the human skeleton and ability to continuously remodel. Its dense nature makes it clearly distinguishable from other tissues by means of imaging. Through a portrayal of radiodensities, imaging provides both qualitative clues and quantitative metri...
Article
Full-text available
To support the translation of Raman spectroscopy into clinical applications, synthetic models are needed to accurately test, optimize and validate prototype fiber optic instrumentation. Synthetic models (also called tissue phantoms) are widely used for developing and testing optical instrumentation for diffuse reflectance, fluorescence, and Raman s...
Article
Recovery of Raman or Fluorescence signatures from within thin tissues benefits from model-based estimation of where the signal came from, especially if the signal passes through layers in which the absorption or scattering signatures distort the signal. Estimation of the signal strength requires appropriate normalization or model-based recovery, bu...
Article
Allografts and other bone-grafts are frequently used for a variety of reconstructive approaches in orthopaedic surgery. However, successful allograft incorporation remains uncertain. Consequently, there is significant need for methods to monitor the fate of these constructs. Only few noninvasive methods can fully assess the progress of graft incorp...
Article
Full-text available
In this study, we report adaptation of Raman spectroscopy for arthroscopy of joint tissues using a custom-built fiber-optic probe. Differentiation of healthy and damaged tissue or examination of subsurface tissue, such as subchondral bone, is a challenge in arthroscopy because visual inspection may not provide sufficient contrast. Discrimination of...
Article
Full-text available
Projective transformation is a mathematical correction (implemented in software) used in the remote imaging field to produce distortion-free images. We present the application of projective transformation to correct minor alignment and astigmatism distortions that are inherent in dispersive spectrographs. Patterned white-light images and neon emiss...
Article
Full-text available
The use of bone structural allografts for reconstruction following tumor resection is widespread, although successful incorporation and regeneration remain uncertain. There are few non-invasive methods to fully assess the progress of graft incorporation. Computed tomography and MRI provide information on the morphology of the graft/host interface....
Article
As part of our ongoing assessment of bone tissue composition and structure, we report the first experimental protocols of a prospective study to investigate the potential of using Raman spectroscopy to diagnose and predict skeletal fragility in postmenopausal osteoporosis patients. This multi-center study will assess several potential spectroscopic...
Article
As part of our ongoing assessment of bone tissue composition and structure, we report the first experimental protocols of a prospective study to investigate the potential of using Raman spectroscopy to diagnose and predict skeletal fragility in postmenopausal osteoporosis patients. This multi-center study will assess several potential spectroscopic...
Article
Light can be coupled into imaging spectrographs through the use of fiber-optic bundles. Ideally, the collected spectra from adjacent optical fibers should be resolved and independent. However, this assumption breaks down if a partial overlap of adjacent fibers on the detector CCD results from either diffraction or uncorrected monochromatic aberrati...
Article
Raman spectroscopic measurement of bone composition has shown promise as a medical diagnostic by measuring the molecular composition of the bone mineral and matrix. We previously demonstrated proof-of-principle transcutaneous Raman spectroscopy bone measurements in human cadavers. In this paper, we discuss further optimization of the instrumental c...
Chapter
Raman spectroscopy can be used to non-destructively add image contrast in visualizing structures and dynamics in living systems and materials. Image contrast can be derived from any information contained in Raman spectra, including band intensities, positions and widths. Because these parameters are functions of the local physical and chemical envi...
Article
Full-text available
Measured Light scattering properties can be used to improve quantitative spectroscopic analyses of turbid samples. Instruments currently used to measure scattering coefficients are not optimised for portability. A hand-held, dual-wavelength instrument was developed and validated for rapid measurement of reduced scattering coefficients in tandem wit...
Article
Full-text available
Raman spectroscopy can provide valuable information about bone tissue composition in studies of bone development, biomechanics, and health. In order to study the Raman spectra of bone in vivo, instrumentation that enhances the recovery of subsurface spectra must be developed and validated. Five fiber-optic probe configurations were considered for t...
Article
Full-text available
Raman spectroscopy of bone is complicated by fluorescence background and spectral contributions from other tissues. Full utilization of Raman spectroscopy in bone studies requires rapid and accurate calibration and preprocessing methods. We have taken a step-wise approach to optimize and automate calibrations, preprocessing and background correctio...
Article
Full-text available
We describe the use of Raman spectroscopy to investigate synovial fluid drops deposited onto fused silica microscope slides. This spectral information can be used to identify chemical changes in synovial fluid associated with osteoarthritis (OA) damage to knee joints. The chemical composition of synovial fluid is predominately proteins (enzymes, cy...
Article
A method for applying two-dimensional correlation analyses to N-way data is presented, which compactly displays trends in the data. Interpreting large multi-dimensional data sets obtained from hyphenated instruments is difficult. Several methods of applying two-dimensional correlation analyses to N-way data are examined. To visualize trends occurri...
Article
This thesis explores four methods for improving quantitative diffuse reflectance spectroscopy in light scattering media. In the introduction theories of light propagation in scattering media, relevant instrumentation for measuring light scattering properties, spectral data processing methods, and spectroscopically active bioanalytes are outlined. N...

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